Disease overview

Congenital Myasthenic Syndrome is a neuromuscular disease characterized by severe generalized skeletal muscle weakness that is typically induced by exercise. Puppies tend to appear normal but then suffer episodes of collapse after a few minutes of exercise or play. After resting, the dog will be back to normal. This is due to reduced synthesis of acetylcholine, a neurotransmitter that is necessary for muscle activation.

Gene name

COLQ

Inheritance

Autosomal recessive

Signs and symptoms

Clinical signs typically appear after 5 to 30 minutes of activity or exercise. Affected puppies will play normally and then begin to take shorter strides, and eventually collapse. After rest, signs will disappear (only to reappear if activity is repeated). Early onset occurs between 6 to 12 weeks of age. The severity of this disease can vary significantly.

How is it diagnosed

A veterinarian will conduct a thorough exam, including a review of health history and any clinical signs. Laboratory tests and/or a neurological exam may be conducted. Genetic testing is necessary to determine if there is an underlying genetic cause, which can assist veterinarians with diagnosis and help breeders identify affected and carrier dogs.

Breeds at higher risk

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Citations

Rinz CJ, Levine J, Minor KM, Humphries HD, Lara R, Starr-Moss AN, Guo LT, Williams DC, Shelton GD, Clark LA. A COLQ missense mutation in Labrador Retrievers having congenital myasthenic syndrome. PLoS One. 2014 Aug 28;9(8):e106425. doi: 10.1371/journal.pone.0106425. PMID: 25166616; PMCID: PMC4148433.

Tsai KL, Vernau KM, Winger K, Zwueste DM, Sturges BK, Knipe M, Williams DC, Anderson KJ, Evans JM, Guo LT, Clark LA, Shelton GD. Congenital myasthenic syndrome in Golden Retrievers is associated with a novel COLQ mutation. J Vet Intern Med. 2020 Jan;34(1):258-265. doi: 10.1111/jvim.15667. Epub 2019 Nov 26. PMID: 31769119; PMCID: PMC6979411.

Disclaimer

Disease diagnosis and treatment should always be performed by a veterinarian. The following information is for educational purposes only.